Each of us uses about 145 litres each day, but the average household roof could harvest 85,000 litres of rainwater a year - pure, chemical-free, soft water - perfect for crops and plants in the garden and ideal to wash the car of clean the terrace. Here are lots of good ideas to help so we'll need to water less:
- mulch the plants
- remove any weeds
- improving the soil so it retains water better
- space plants densely
- put in plants with low water requirements (see below).
- harvest rainwater and reuse household water
- limit lawn space
- use drought-tolerant grasses and allow them to grow longer
- leave cut grass on the lawn as a mulch
- use permeable surfacing like gravel for hard landscaping;
- fill containers with peat-free compost (green waste, loam or coir-based composts retain water better)
- water efficiently by thoroughly soaking the base of each plant in need of water (at a rate of at least 10 litres per square metre) - in the early morning or evening - to avoid transpiration.
The best way for householders to harvest rainwater for garden purposes is to place a container under a downpipe with a diverter which directs any overflow to a ground drain.
House roofs are obvious candidates, but don't forget greenhouses, garages, conservators, even sheds.
If a water butt isn't enough, go for an above-the-ground tank in agricultural corrugated metal; a complete underground system with pumps and filters; or a self-build system to purify household and grey water.
A drip-watering system, delivering moisture direct to the root zones is especially useful in vegetable gardens. when they can be hidden along the raised beds.
If you're really committed you can establish a garden wetland to purify grey water, mimicking a natural wetland where plants, microbes and animals convert pollutants to biomass, leaving clean water.
Most vegetables need water to establish but these must be kept watered throughout the season:
- salad leaves and lettuces
- spinach
- summer cabbage
- cauliflower
- celery
- celeriac
- fennel
- runner beans
- anything which grows in the greenhouse, especially cucumbers and tomatoes
Plants which need less water include:
- Ones with silver grey leaves: cistus, santolina and artemesia
- Plants with aromatic oils: lavender, rosemary and thyme.
- Plants which store water: succulents and agaves.
- Plants with long tap roots: verbascums, hoilyhocks and umbellifers.
- Plants with hairy leaves: salvias, verbascums and comfreys.
- Sword-like leaved plants: yucca, cordylines and phormiums.
- Native plants suited to local conditions.
- Perennials need less watering than annuals and bedding plants.
DIY GARDENING BOOKS
- A Guide to Waterwise Gardening by Michael Littlewood
- The Resilient Garden by Marilyn Abbot
- Gardening in a Changing Climate by Ambra Edwards
- Waterwise Gardening by Ian Cooke